You know you’re in a literary power scene when the guy who steals your seat is Philip Roth. The iconic author of “American Pastoral” saw a spot he preferred to the one he was assigned yesterday at a Michael’s luncheon honoring William Styron’s widow, Rose, and surreptitiously swiped the nearby seat, which wound up belonging to comic Richard Belzer. Also seen settling in at the intimate gathering — hosted by Open Road Media’s Jane Friedman and Jeffrey Sharp — was “Crazy Heart” director Scott Cooper, who’s adapting Styron’s “Lie Down in Darkness” as a feature film for Open Road, and Mike Nichols. Rose Styron recently edited “Selected Letters of William Styron” for Random House.